style: 优化 audio 样式

src/components/AudioPlayer/index.js

         });
       this.player.onpause = () =>
         this.setState({ isPlaying: false, isLoading: false });
-      this.player.onplay = () => this.setState({ isLoading: true });
+      // this.player.onplay = () => this.setState({ isLoading: true });
       this.player.ontimeupdate = event =>
         this.setState({ currentDuration: event.target.currentTime });
       this.player.src = src;
     let playIconElem;
 
     if (isLoading) {
-      playIconElem = <img src={iconLoading} alt="iconLoading" />;
+      playIconElem = (
+        <img className="icon-loading" src={iconLoading} alt="iconLoading" />
+      );
     } else if (isPlaying) {
       playIconElem = <Icon className="pause" type="pause" />;
     } else {

src/components/AudioPlayer/index.less

     font-size: 14px;
   }
 
+  .icon-loading {
+    width: 100%;
+    height: 100%;
+  }
+
   .slider {
     margin: 0 0 0 16px;
     width: 195px;